JPH0735743A - Decompression operated assembly containing tube of coagulation accelerating plastic - Google Patents

Abstract

PURPOSE: To overcome the defect of plastics that coagulation is delayed, while maintaining the advantages of plastics, by plasma processing the interior wall surface of a plastic blood-collecting container with a processing gas. CONSTITUTION: A plastic tube 10 in this blood-collecting assembly has a bottom wall 12 defining a closed end 14 and a side wall 16 defining an open end 18, is covered with a pierceable bulkhead 24, and exhausted. An interior wall surface 20 is further worn as it is processed with a plasma caused by a processing gas. Processing with the plasma increases the coagulation speed of a blood sample. The plasma processing results in the introduction of a polar functional group on the surface of the plastic. The functional group is derived from the processing gas used for producing the plasma. For example, the surface contains oxygen, nitrogen, or sulfide dioxide after the plasma processing. These groups induce on the plasma processed surface a coagulation activation characteristic similar to or greater than that of glass.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION This invention relates to blood collection and, more particularly, to a plastic blood sampling assembly.

[0002]

Blood samples are usually made, for example, from a glass VACUTAINER ™.
Collected in evacuated tubes such as tubes (Becton, Dickinson and Company). Insert one end of the double-ended needle into the patient's vein. The other end of the needle then punctures a septum covering the open end of a Vacutainer ™ tube, which draws a blood sample through the needle into the tube with the vacuum in the tube. Using this technique, multiple samples can be taken with a single needle puncture of the skin. Plastic tubes have also been proposed for blood collection. Plastics have many advantages, for example, they are less fragile than glass tubes, they weigh less in transit and are easily discarded by incineration.

Blood collected in an evacuated tube must often be clotted prior to clinical examination. It is desirable to form a blood clot that is as fast and completely dense as possible and facilitates a clean separation of blood clots from the serum layer by centrifugation.
To achieve this end, both plastic and glass blood collection tubes often use clot activators.
Typical activators are diatomaceous earth and inorganic silicate particles,
Or biochemical agents such as ellagic acid and thromboplastin. In a series of commercially available blood collection tubes, for example, a coating of silicate particles in polyvinylpyrrolidone (PVP, a water-soluble polymer) adheres to the inside of the tube. As blood enters the tube, the PVP melts and the silicate particles separate, allowing coagulation to begin. PVP enters both serum and blood clots.

A problem with particulate activators is that the finely dispersed particles do not completely pellet with the clot and may therefore contaminate the serum layer and interfere with some blood assays. In addition to this, particles suspended in serum may clog the automated hematology analyzer. On the other hand,
Soluble biochemical activators are disadvantageous because they cannot be easily separated from either serum or blood clots and interfere with both chemical and hematological analysis. In particular for very specific applications, such as blood banks, it is unacceptable to have either soluble activators or particles as these cells are used for blood group analysis in the clot cell mass. For this reason, samples for blood banks are usually taken in glass tubes and rely on the clot-activating properties of the glass to cause clotting. In blood collection techniques, it increases the rate of blood coagulation but does not leave any soluble or particulate matter in the serum layer or in the blood clot during centrifugation and becomes part of the blood clot, thus not potentially interfering with laboratory tests, and There is a need for such a device, especially in the blood bank method. The present invention aims to meet this need.

[0005]

A blood collection assembly includes a tube having a bottom wall continuous to a side wall. The side wall defines an open end and the bottom wall defines a closed end. The bottom wall and the side wall together define an inner wall surface. The open end is covered with a pierceable septum and the tube is evacuated. The inner wall surface is treated with plasma from the process gas and is further abraded to have a large surface area.

A second aspect of the invention is a method of making the device of the invention. In one embodiment of the method, the inner wall surface of the tube is treated with a plasma to introduce foreign atoms to the wall surface. In a second method embodiment, the inner wall surface is abraded to roughen it for a larger surface area. In the preferred method, the inner wall of the tube is both abraded and plasma treated.

Thus, the present invention provides a plastic tube which retains the advantages of plastic and overcomes the disadvantages of plastic slow and slow clotting. Plasma treatment and abrasion modify the chemistry of the inner wall of the tube, thereby promoting clotting, but without the presence of particulate or soluble clot activators or binders that contaminate either serum or clots. The assembly of the present invention is particularly suitable for operating blood banks.

[0008]

While the present invention is satisfied by many different forms of embodiments, there are now set forth detailed preferred embodiments of the invention, which are provided as an illustration of the principles of the invention. It should be understood that the invention is not limited to the embodiments described and described. The scope of the invention will be determined by the appended claims and their equivalents.

The blood collection assembly of the present invention may be any container having a closed end and an open end. Suitable containers are eg tubes, vials, flasks etc., preferably tubes. Therefore, the present invention will hereinafter describe the preferred tube. FIG. 1 shows the tube of the present invention. The tube 10 has a bottom wall 12 defining a closed end 14 and a side wall 16 defining an open end 18. Bottom wall 12 and side wall 14 are continuous and together define an inner wall surface 20. The area 22 of the inner wall surface 20 is rough as a result of wear. FIG. 1 shows that only a portion of the inner wall surface near the bottom of the tube is rough, but this is simply because of the invention which keeps the top of the tube sufficiently transparent due to the clear visibility of the serum layer. It is only a preferred embodiment. Of course, it is clear that the entire inner surface or any other part may be worn if desired. The open end 18 of the tube 10 is covered with a pierceable septum 24.
The pipe 10 covered with the partition wall 24 is exhausted. Evacuated tubes for blood collection are standard in the art, such as the Vacutainer ™ brand tubes (Becton, Dickinson and Company).

The tube may be plastic. Suitable plastics are polyethylene terephthalate (PET), and preferably polystyrene (PS). The tube may be of any size, but the present invention is particularly suitable for evacuated blood collection tubes.

These tubes are generally cylindrical and have a length of 50.
It is about 150 mm and the diameter is about 10 to 20 mm.

In accordance with the present invention, it has been found that treating the tube with plasma surprisingly increases the rate of blood sample coagulation. The plasma originates from any suitable processing gas. Representative of suitable process gases are, of course, without limitation, nitrogen, ammonia, carbon dioxide, sulfur dioxide, air and oxygen, with air and oxygen being preferred. The tube is placed open end up between the electrodes of a conventional plasma generator equipped with a pressure gauge, gas inlet and vacuum connector. Suitable electrodes are any conductive material, with stainless steel and aluminum being preferred. The size and shape of the electrodes are not critical. Any suitable ionizing plasma is used, for example a plasma generated by a corona discharge or preferably a glow discharge.

A wide range of power settings, frequencies, and durations of plastic surface exposure to plasma are used. The ranges for these parameters that bring advantages are:
DC or AC power levels up to 200 watts, about 0.
1 to about 50 megahertz and about 0.1 to 30 minutes.
The preferred ranges are 10-50 watts and 10-2, respectively.
0 megahertz and 2-10 minutes. Any gas pressure can be used, however, the gas pressure may advantageously be maintained below 5 mmHg to benefit from lower voltage requirements. Ambient temperature is preferred for plasma generation.

As a result of the plasma treatment, polar functional groups are introduced on the surface of the plastic. The functional group depends on the processing gas used to generate the plasma. For example, after plasma treatment, the surface contains oxygen, nitrogen or sulfur dioxide.
These groups cause the plasma-treated surface to develop coagulation-activating properties that are equal to or somewhat greater than glass. The examples and figures show the accelerated rate of clotting of plasma treated plastic surfaces compared to that of glass and untreated plastic.

In the preferred embodiment of the invention, the inner wall surface of the tube is abraded to a rough surface, thereby increasing the surface area. The plasma treatment is performed before wear or preferably subsequent to wear. The surface is roughened by conventional chemical or mechanical methods or during the tube forming process. Most conveniently, the surface is simply rubbed with an abrasive such as sandpaper or emery paper.
Medium size sandpaper has been found to increase surface area most, but the abrasive particle size is not limited. Most preferably, the portion of the inner wall surface at or near the bottom of the tube is roughened and the rest of the tube is not roughened, which maintains maximum transparency of the tube for observing the serum layer after centrifugation. Because it does. Of course, it seems preferable to treat the entire inner wall surface with plasma.

[0016]

【Example】

Example I The coagulation activating properties of the plasma-treated tube of the present invention were measured by
S and glass tubes and thrombocytopenic plasma (PP
P) or whole pig blood was evaluated by comparison with the time required to clot. PPP is citric acid pig whole blood (environmental diagnostic (En
(Biological Diagnostics)) was prepared by separating the cells by centrifugation. P
Approximately 3 ml of PP or whole blood was added to the tube and the temperature was equilibrated to room temperature in a water bath for 15 minutes. After equilibration, add 200 μl 0.2M CaCl ₂ per ml of PPP or blood,
Clot started. The tube contents were mixed in a laboratory inversion mixer and the clotting time was noted for each tube type. Coagulated PPP or whole blood was distinguished from non-coagulated by a clear change from a flow state to a gelatin state that did not flow in the tube on rotation. Clotting time was measured at this point.

Example II Plasma Treatment A. PS tube (Becton Dickinson, FALCON (trade name), 13 mm x 75 mm)
Is exposed to an oxygen plasma generated in a conventional planar diode plasma unit. The unit is then operated at about 50 watts at a frequency of 13.56 MHz and a pressure of 200-300 mtorr for about 5 minutes to produce a highly oxidized surface chemistry.

B. In the same manner as in A, shock-modified PS
(K resin, Philips), polypropylene (PP) tubing (ESCORENE (TM), Exxon) and PET tubing (Eastman Grade 2182).
And tubes 1042) were plasma treated. The clot activation properties of the tubes of the present invention and control tubes are shown in Figure 2, the tube types are as follows: whole blood use: 1. PS Falcon (trade name) 2. Plasma Treated Plasma Treated PS Falcon ™ PPP Use: Glass 4. Plasma treated glass 5. PS Falcon (trade name) 6. Plasma treated PS Falcon ™ 7. PSK resin 8. Plasma-treated PSK resin 9. PP 10. Plasma treated PP 11. PET2182 12. Plasma treated PET2182 13. PET1042 14. Plasma Treated PET 1042 As can be seen in Figure 2, plasma treatment of PS tubes shortens the coagulation time of whole blood by more than 8 times (tube types 1 and 2). The clotting time of PPP in plasma treated PS is reduced by a factor of about 2.5 compared to non-plasma treated PS (tubes 5-8). The clotting time of PPP is also about 2-in PET tubes (tubes 11-14) in plasma treatment.
2.5 times shorter, but PP plasma treatment is P
Has almost no effect on PP coagulation (tubes 9 and 1
0).

Example III The lower half of the PS tube (Falcon ™) was mechanically rubbed with medium size sandpaper to roughen the inner wall surface. FIG. 3 compares the clotting times observed in these tubes before and after plasma oxidation performed as described in Example II. In Figure 3, the tube types were as follows: PS Falcon (trade name) 2. Plasma-treated PS Falcon (trade name) 3. Abrasion PS Falcon (trade name) 4. Abrasion and Plasma Treated PS Falcon ™ Abrasion to obtain a rough surface with a larger surface area is PPP
Clot time of about 30% (comparing tube 3 and control tube 1), and rough surface plasma treatment (tube 4) can reduce clotting time by 5 times compared to control tube 1. it is obvious.

[Brief description of drawings]

FIG. 1 is a perspective view of a blood collection tube assembly of the present invention.

FIG. 2 is a diagram comparing blood coagulation rates in control tubes and representative tubes of the present invention.

FIG. 3 compares blood coagulation rates in control tubes and representative tubes of the present invention.

[Explanation of symbols]

 10 pipe 12 bottom wall 14 closed end 16 side wall 18 open end 20 inner wall surface 22 face 24 pierceable partition wall

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Claims (10)

[Claims] 1. A plastic blood collection container having a bottom wall and a sidewall defining an open end covered by a pierceable septum, the bottom wall, sidewall and septum defining an evacuated interior volume of the container. Enclosing, the inner wall surface of the vessel is treated with plasma from the process gas, and the plasma treated wall surface causes an accelerated rate of blood coagulation in the vessel as compared to the rate in the otherwise non-plasma treated vessel. Blood collection assembly including container. 2. The apparatus of claim 1 wherein said container is selected from the group consisting of polystyrene, impact modified polystyrene and polyethylene terephthalate. 3. The apparatus of claim 1, wherein the processing gas is selected from the group consisting of air, oxygen, nitrogen, ammonia, carbon dioxide and sulfur dioxide. 4. A plastic blood collection container having a bottom wall and a sidewall defining an open end covered by a pierceable septum, the bottom wall, sidewall and septum defining an evacuated interior volume of the container. Enclosure, the inner wall surface of the container is abraded and has a rough surface and is treated with plasma from the process gas, otherwise promoting the coagulation of blood in the container compared to the velocity in the same non-abrasion, non-plasma treated container A blood collection assembly that includes a container for accelerating speed. 5. The apparatus of claim 4, wherein the container is polystyrene and the processing gas is oxygen. 6. The following steps: a) exposing the inner wall surface of a plastic container having an open end to plasma from a processing gas to obtain a plasma treated inner wall surface; b) covering the open end with a pierceable septum; c) A method for producing a plastic blood sampling assembly, which comprises exhausting the container covered with the partition wall. 7. The method of claim 6 wherein said container is fabricated from a plastic selected from the group consisting of polystyrene, impact modified polystyrene and polyethylene terephthalate. 8. The method of claim 6, wherein the processing gas is selected from the group consisting of air, oxygen, nitrogen, ammonia, carbon dioxide and sulfur dioxide. 9. The following steps: a) abrading the inner wall surface of the plastic container having open ends to obtain a rough inner wall surface having a larger surface area than that of the plastic container before the abrasion; b) the rough inner wall A method for producing a plastic blood sampling assembly, which comprises exposing the surface to plasma from a processing gas; and c) covering the open end with a puncturable septum. 10. The method of claim 9, wherein the container is polystyrene and the processing gas is oxygen.